Circulating-tube for steam-boilers.



H. S. VINCENT.

CIRCULATING TUBE FOR STEAM BOILERS. APPLICATION FILEDYJAN. 26, 1914.

1,09'7;830. Patnted May 26, 1914.

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HARRY S. VINCENT, OF RIDGEWOOD, NEW JERSEY.

CIRCULATING-TUIBE FOR STEAK-BOILERS.

Specification of Letters Patent.

Patented May 26, 1914.

Application filed January 26, 1914. Serial No. 814,357.

To all whom it may concern:

Be it known that I, HARRY S. VINCENT, of Ridgewood, in the county of Bergen and State of New Jersey, have invented a certain new and useful Improvement in Circw 'lating-Tubes for Steam-Boilers, of which improvement the following is a specification.

My invention relates-to'tub'es designed for promotingthe circulation of water between in Letters Patent of the'United States No.

40,630, granted and issued to John P. Laird,

under date of November 17, 1863.

The object of my invention is to provide means, of ready and inexpensive applicability in water leg fireboxes of the present standard types, whereby the circulating capability of tubes of the class referred to will be materially increased by causing them to be supplied with water at a lower temperature than is attainable under the ordinary construction, and correspondingly reducing the tendency of the water to be converted into steam in its traverse through them.

To this end, my invention, generally stated, consists in a steam boiler circulating tube having an extension by which its inlet is located within the water leg from which its water supply is derived, and adjacent to the outer sheet thereof.

The improvement claimed is hereinafter fully set forth.

In the accompanying drawings: Figure 1 is a vertical longitudinal section through the firebox of a locomotive boiler, illustrating an application of my invention; Fig. 2, a simllar section, on'an enlarged scale, through the front water leg of the firebox; Figs. 3 and 4, sections, similar to Fig. 2, illustrating structural modifications; and, Fig. 5,atransverse section, onthe line a a of F1g.-3. I

It has been demonstrated by tests that .the water in contact with and adjoinin the inner sheets of a water leg firebox, is otter than that adjoining the outer sheets, and it has also been shown that, in some cases, by reason of imperfect circulation, bubbles of steam are formed on the water sides of the inner sheets, preventing the water from contacting therewith and thereby causing the sheets to crack. Although the circulating tubes designed to effect more perfect circulation are made of as large transverse sectional area as practicable, a tendency exists for the water passing through them to fiash' int-o steam, qthereby defeating their purpose, this being due to the fact that they pass through the hottest portion of the tire box. My invention is desi nod to effect the supply of water to the circulating tubes at the lowest temperature available and thereby to counteract the detrimental tendency referred to, and correspondingly facilitate the circulation of water through the tubes.

My invention is herein exemplified as applied in a locomotive boiler firebox of one of the present approved standard. types, comprising an inside firebox, the members of which are a tube sheet, 1, sidesheets, 2, a back sheet, 3, and'a crown sheet, 1, and an outside firebox, the members of which are a throat sheet, 1, side sheets, (not shown in the drawing), a back sheet, 3, and a top or wrapper sheet, 45*. The water spaces of the water legs at the front, rear, and sides of the firebox are closed by a mud ring, 5, and the sheets forming the inner and outerwalls of the water legs areconnected by stay bolts, 6. The crown sheet, 4:, and top sheen-4 are connected by so-called radial stay bolts, 7. Communication between the front and rear water legs is established by a plurality of circulating tubes, 8, which are fixed, at theiropposite ends, in holes in the tube sheet, 1, and back sheet, 3, respectively, and are inclined upwardly from the former, at a level below the boiler tubes, to the latter, at a level slightly below the crown sheet. The circulating tubes, 8, perform the additional function of supporting a brick arch, 9, in

the usual manner. Access to the interior of the circulating tubes is,when required, afforded by plugs, 10, 11, secured removably in the back sheet, 3, and throat sheet, 1, respectively, opposite the ends of the circulating tubes.

In the practice of my invention, I pro vide a circulating tube 8, which is secured, by the ordinary expanding operation, in the back sheet, 3, and tube sheet, 1, and in size, position, and relation to said sheets, accords substantially with those heretofore known in the art, but which, under my invention, instead of terminatin at its lower end, at the tube sheet, 1, an being open thereat to the water space, asin prior practice, is ex tended into the water space of the front water leg, its extension, 8, which may be either integral with it, as shown in Figs. 1 and 2 or formed of a separate section of pipe, as in Figs. 3 and a, terminating within the water space, adjacent to the inner side of the throat sheet, 1, and as close thereto as will enable an inlet passage for water, from the water space to the circulating tube, of substantially the full sectional area of the inside of the extension, to be presented, at, and only at, the end of the extension which adjoins the throat sheet, thus preventing the entrance of water at any point in the length of the extension except adjacent to said sheet. In order to minimize the distance of the outer end of the extension, 8 from the throat sheet, serrations, 8, may be formed in said end, as shown in Fig. 2. It will be seen that by this construction, the relatively cooler water which adjoins the outer sheet of the waiter leg from which the water supply of the circulating tube is derived, (the throat sheet, 1) will be entrained into the circulating tube, 8, instead of the relatively hotter water which adjoins the sheet next the fire (the tube sheet, 1) as in prior practice, the entrance of which hotter water being prevented by the periphery of the extension beingclosed at the tube sheet and for the major portion of the distance therefrom to the throat sheet.

Figs. 3 and 5 illustrate a modification of structural detail, involving the same essential feature and operative principle, in which the extension, 8, of the circulating tube, is a separate piece, fitted into the outer end of the circulating tube, and secured, at its outer end, by screws, 8 to an inwardly projecting cage, 11, formed on the plug, 11, which plug is screwed into the throat sheet, 1, in

line axiall with the circulating tube and extension. ater is. admitted to the extension through lateral inlet openings, 11", in the cage, the aggregate area of which inlet openings i's-not less than the transverse area of the inside of the extension.

The structural modification shown in Fig. 4, accords-substantially with that last above described, differing therefrom in the articular that, in this case, the plug, 11,- w ich, as before, carries a laterally apertured cage, 11, is not screwed into the throat sheet, but

,within the discretion of a constructor skilled in the art, without departure from the spirit and operative principle of my invention,

and I do not, therefore, limit -myself to the specific embodiments thereof which are herein exemplified.

I claim asmy invention and desire to secure by'Letters Patent:

1. A circulating tube for steam boilers having an extension which projects into the water leg from which its water supply is derived, and is closed thereto otherwise than by an inlet end located as closely adjacent to the outer sheet thereof as will afford full admission of suppl water.

2. In a steam boiler, the combination, with two of the water legs thereof, of a circulating tube connecting said water legsand having an extension rojecting into the water space of the leg rom which water supply is'derived, and closed thereto otherwise than by an inlet end located as closely adjacent to the outer sheet thereof as will suffice to afiord full admission of supply water.

3. In a steam boiler, the combination, with two of the water legs thereof, of a circulating tube connecting said water legs, a

lug fixed in the outer sheet of the water leg from which water supply is derived, and an extension circulatin pipe section fitting the circulating tube an fixed to the plug, said extension section being open to the water leg adjacent to the outer sheet thereof.

4:. In a steam boiler, the combination, with two of the water legs thereof, of a circulating tube connecting said water legs, a laterally apertured plug fixed in the outer sheet of the water leg from which water supply is derived, and an extension circulating pipe section fitting the circulating tube and fixed to the plug.

HARRY S. VINCENT.

Witnesses:

J. SNownEN BELL, EDWARD A. WRIGHT. 

